And on the Seventh Day the Lord Overclocked

Now this is where the real fun begins. If it isn’t already, tick the checkbox marked “Enable driver level hardware overclocking” near the top of the window. There are those who prefer hardware-level rather than driver-level overclocking. The main plus of driver-level overclocking is that it is the safer of the two methods as it runs through the driver’s overclocking interface. I also find it generates the clock cycles more neatly as a result, hardware-level overclocking often tending to “jump” as it generates the MHz numbers. As you would expect hardware overclocking runs totally independent of the drivers, and there is no screen flicker at boot up as occurs with driver overclocking, but other than that there are no real differences as far as I know of (thanks to Fishybawb).

Personally I prefer driver-level, but that’s just me, so let’s stick with driver-level for now.

Upon ticking the checkbox you will probably be presented with a message recommending that you restart the computer to allow Rivatuner to detect clock speeds for your cards. In most cases simply clicking “Detect Now” will do the trick. However, if the clocks come up incorrectly you should deselect the checkbox, cancel all actions, and restart the process, but select “Reboot” rather than “Detect Now” when Rivatuner retries to detect the clock settings.

You should with any luck be greeted by a screen showing your stock clock speeds and sliders for increasing or decreasing them (see image below). The top value is that of your GPU core -- this is the processor for the card and tends to get quite warm and won’t overclock as well as the card’s memory, values for which are listed below. In my case the stock speeds for my gf4 ti4200 (64mb) are 250MHz core and 513MHz memory, having said that the memory on my card is rated for normal operation at 555Mhz, so I reckon I can make this baby sweat a little more ;)

The next steps are to check the “Apply overclocking . . .” box and then to drag the sliders up in 10Mhz-increments for both core and memory. Values can be fine-tuned by using the arrow keys rather than dragging. Once this is done, click “Test.” Once the test procedure has completed click ”Save” and then “Apply,” which should leave you with the following:

Once you have saved your settings, it’s time to test if your overclock is fully stable. To do this I’d recommend running a quick bench, say a single run of 3dmark 2001 or play a quick five-minute stint of a 3D accelerated game, GT Interactive’s Driver, often serving as a good tester for me. If you don’t encounter any visual artefacts such as texture tearing or other visual oddities then you know that the overclock is fine, so you can jump back into Rivatuner and raise your clocks another 10MHz, and bench again.